67 1000 | ( | 61863 1000 | − | y | ) | + | 57 1000 | y | = | 3429 1000 |
| 方程左边 = | 67 1000 | × | 61863 1000 | − | 67 1000 | y | + | 57 1000 | y |
| = | 4144821 1000000 | − | 67 1000 | y | + | 57 1000 | y |
| = | 4144821 1000000 | − | 1 100 | y |
4144821 1000000 | − | 1 100 | y | = | 3429 1000 |
| - | 1 100 | y | = | 3429 1000 | − | 4144821 1000000 |
| - | 1 100 | y | = | - | 715821 1000000 |
715821 1000000 | = | 1 100 | y |
1 100 | y | = | 715821 1000000 |
| y | = | 715821 1000000 | ÷ | 1 100 |
| = | 715821 1000000 | × | 100 |
| = | 715821 10000 | × | 1 |
| y | = | 715821 10000 |
| y | = | 71.5821 |